1. Technical Field
This invention relates to the use of wavelength emission data for the real time quantitative analysis of acrylamide levels in food.
2. Description of Related Art
In recent times, a wide variety of foods have tested positive for the presence of acrylamide monomer. Acrylamide has especially been found primarily in carbohydrate food products that have been heated or processed at high temperatures. Examples of foods that have tested positive for acrylamide include coffee, cereals, cookies, potato chips, crackers, pretzels, french-fried potatoes, breads and rolls, and fried breaded meats. In general, relatively low contents of acrylamide have been found in heated protein-rich foods, while relatively high contents of acrylamide have been found in carbohydrate-rich foods, compared to non-detectable levels in unheated and boiled foods.
Acrylamide has not been determined to be detrimental to humans, but its presence in food products may be undesirable. As noted previously, relatively higher concentrations of acrylamide are found in food products that have been heated or thermally processed. The reduction of acrylamide in such food products could be accomplished by reducing or eliminating the precursor compounds that form acrylamide, inhibiting the formation of acrylamide during the processing of the food, or removing acrylamide from the product prior to consumption.
The measurement of acrylamide in food products is a time consuming procedure. U.S. Patent Application Publication No. 2006/0029992 discloses two ways to detect and quantify the acrylamide content in food products. The first way is liquid chromatography in tandem with mass spectrometry (LC-MS/MS) and the second way is gas chromatography-mass spectrometry (GC-MS). These two tests require an extensive lab environment and a lab professional to conduct the testing. The tests are therefore time intensive and fail to provide a quick way to test for acrylamide in food products. Consequently, a need exists for a real-time way to measure acrylamide levels in food products.
One article (Segtnan, et al, “Screening of acrylamide contents in potato crisps using process variable settings and near-infrared spectroscopy,” Mol. Nutr. Food. Res. 2006 50, 811-817), the entirety of which is hereby incorporated by reference, discloses measuring NIR spectra with the focus of the spectral analysis occurring on bands originating from water, carbohydrates, and fat rather than the amide bonds. The highest R-value disclosed in the article is a value of 0.952, meaning the highest R-squared value, which is an indicator of correlation between predicted and actual values is 0.906. A need exists for a more accurate predictor of acrylamide concentration in a food product.
Further, while it would be desirable to measure on a real time basis the level of acrylamide in a food product being produced on a commercial food product manufacturing line, it would also be desirable to use real time acrylamide measurements to reduce the level of acrylamide in a food product on a real time basis. Consequently, such heightened accuracy of a real-time acrylamide measurement is especially important if the real-time measured value of acrylamide is used to adjust process variables to manually or automatically lower the acrylamide level in a food product being manufactured on a food manufacturing line.
One prior art method for reducing acrylamide in food products, as illustrated by U.S. Pat. No. 7,393,550, assigned to the same assignee as the present invention, occurs by heating the food product at lower temperatures when the food has achieved lower moisture contents. Thus, a potato slice can be par-fried to a moisture content of 4% and finish dried in an oven at a temperature of less than 120° C. until a moisture content of less than 2% is achieved. However, it is very difficult to monitor and/or control many of the variables affecting the formation of acrylamide in individual food pieces, even when such pieces are manufactured on the same food manufacturing or production line. For example, individual potato chips made by a par-fry process can still have different levels of acrylamide because some potato chips may stay in the fryer longer than other chips, or some raw potatoes may have higher levels of reducing sugars, or some raw potatoes may have other defects that cause high levels of acrylamide. Consequently, a need exists for a way to reduce the variability of acrylamide levels in food products in a food manufacturing line. A need also exists to use a real-time acrylamide monitoring and measurement system to control the food manufacturing process to minimize the amount of acrylamide level in a final food product. A need also exists for a method and system for making food products having more consistent levels of acrylamide. A need also exists to be able to remove, on a real-time basis, foods formed in a food manufacturing process that have acrylamide levels above a certain threshold.